Project description:We report detailed characterization of physiological changes encoded by 63% of all genes within the archaeon Halobacterium salinarum subsp. NRC-1 during routine laboratory growth. While the majority of these changes occur during the transition from rapid exponential growth to the stationary phase, we were also able to detect transient changes in gene expression. This demonstrated the presence of several additional albeit subtle physiological states that exist beyond what might be anticipated from a direct interpretation of the growth profile. Changes in the abundance of several key intracellular metabolites over the growth curve corroborated observations of changes in gene expression of enzymes that catalyze their synthesis. Next, we investigated the roles of general transcription factors (GTFs) in mediating these global growth-associated gene expression changes. This revealed numerous phenotypic perturbations including slowed growth, gas vesicle biogenesis deficiency and morphologic abnormalities upon the overexpression of a single GTF - TBPd. These phenotypes were quantified and were attributed to a perturbation in the regulation of aconitase. Importantly, our results demonstrate why an experiment design as simple as a simple batch culture can be enormously informative of activities and interrelationships of a large fraction of all genes in a microbe. This SuperSeries is composed of the following subset Series: GSE14832: Halobacterium growth in standard growth media: time course GSE14835: Halobacterium growth with added uracil: time course GSE14836: Halobacterium delta-ura3 growth with added uracil: time course Refer to individual Series
Project description:Halobacterium salinarum NRC-1 was grown in CM media, at 37oC in a waterbath with agitation of 125 rpm under constant light. Analysis of transcriptional changes during growth, in addition to mapping of transcriptome structure under the same conditions, provided interesting insights about regulatory logic within prokaryotic coding regions.
Project description:In order to ensure the reproducibility of the transcriptional response of Halobacterium NRC-1 to oxic/anoxic transitions, we repeated global mRNA measurements for the oxygen time series data in GSE5924, except that cultures were equilibrated to low oxygen for 24 hours prior to the start of the experiment rather than 12 hours, and time course sampling continued to 12 hours post-shift to high oxygen rather than stopping at 6 hours. The results of these data suggest that there is good reproducibility between datasets, and that Halobacterium responds robustly to oxic/anoxic transitions. Keywords: time course